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JAMES F. DRUMMOND, oF NEW YORK, N, Y.

Letters Patent No. 72,002, dated December 10, 1867.

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TO ALL WHOM IT MAY CONCERN:

`Be it known that I, vJAMES F. DRUMMOND, of the city, county, and. State of New York, have invented certain new and useful Improvements in Grinding-Mills; and I do hereby declare that the following is a full, clear, and exact description ofthe same, reference being had to the accompanying drawings, making a. portion of this specification, in which- Figure 1 is a vertical longitudinal section of a mill constructed according to my invention.

Figure 2 is a plan view of the same.

Figure 3 is an end view of a portion of the same.-

Similar letters of reference indicate corresponding parts in all the iigures.

This invention relates to that class of grinding-mills in whichthe material is ground or pulverized by the action of loose metal balls, or other similar hard bodies, placed within a rotating drum or cylinder.

The invention consists in certain novel means whereby the more eiiicient distribution of the blast throughout the interior of the cylinder is obtained.

To enable"others to understand the construction and operation of my invention,I' will proceed to describe it with reference to the drawings.V

The drum or cylinder A is provided with tubular journals, indicated respectively'at a and b, which support the same in a suitable frame, B. One of these journals, a, communicates, by means of a tube, e, with receiving-chamber, D, and the other with a blast-pipe, d, connected with a fan or other suitable blower, shown et C. The interior of the journal I1 is contractedat one point around the feed-tube f, and hence madeilaring or conical, as shown in iig. 1, both toward the blast-pipe and toward Athe` cylinder, in order that the sudden expansion of-the air as itleaves the same will better insure its perfect and uniform diffusion or distribution within the cylinder. Situated a't the upper side of this blast-pipe d is a hopper, e, furnished with an adjustable horizontal slide, a, near the bottom thereof, and with a sliding cover at the top, the oilice-of which is to prevent the escape ofthe blast from the cylinder-through the hopper when the machincis in operation. From the hopper e the feedltube f extends to the interior of the cylinder A; VPlaced within the aforesaid cylinder' are any desired number of spherical metal balls, E, or other pieces or blocks of hard material, which, by theirl triturating action during the rotation of the cylinder, reduce the material to be ground to the required iineness.

These balis may be introduced into the cylinder through an opening in one iside thereof, closed when the apparatus is in use by a suitable lid or cover, g. The tubular journal a' is also made daring, in a manner similar to the journal Z, to the end that the coarser particles carried into the said journal a may pass downward upon the sloping sides thereof back into the cylinder. v Y

In using the apparatus, a rotary motion is given to the cylinder by any suitable means, and the paint or other material to be ground is placed iu the hopper e, from which it passes, through the tubef, intothe cylinder, such passage of the material being regulated by adjusting the slide a*, and any escape of air from the cylinder through the hopper being prevented by closing the slide at the top thereof.` The rotating movement ofthe cylinder causes the balls E to trituratc the material, and thus pulverize the same, the fine particles, as fast as formed, being carried, by the blast of air, through the tubular journal a', to the receiving-chamber D, where they are deposited, the spent air being allowed to escape from such chamber in any suitable manner, and the coarser particles deposited in the aforesaid flaring tubular journal passing, down the inclined sides thereof, back into the cylinder, as hereinbei'ore mentioned, so that by these means, as fast as the material is brought to the required degree of iineness, it is automatically removed from the-cylinder, the most eiiicient operation of the blast in separating and removing the finer particlesV being insured by the expansion of the air as it leaves the daring hollow axle b, by the more uniform distribution of the air within the cylinder, as hereinbefore mentioned. If desired, the blast-apparatus, instead of being so located as to drive or force the air into the cylinder, may be arranged between such cylinder and lthe receiving-chamber, in such manner as to draw the air into the aforesaid cylinder, thereby producing the same result as in the case first herein described.

What Iclaim as my invention, and desire to secure by Letters Patent, is- The tubular inlet-journal b, having'its interior contracted around the feed-pipe at one point, and thence flaring toward the cylinder and the blast-pipe, substantially as and for the purpose specied.

' JAS. F. DRUMMOND. Witnesses:

WILLIAM Dones, JOHN Onow. 

